diff options
| author | James Chapman <jchapman@katalix.com> | 2024-07-09 17:28:39 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-07-12 04:09:18 +0100 |
| commit | 2146b7dd354c2a1384381ca3cd5751bfff6137d6 (patch) | |
| tree | aa07fed73fd4a02d5ea621ed8e54eb19536f86bd | |
| parent | tipc: Consolidate redundant functions (diff) | |
| download | linux-2146b7dd354c2a1384381ca3cd5751bfff6137d6.tar.gz linux-2146b7dd354c2a1384381ca3cd5751bfff6137d6.zip | |
l2tp: fix l2tp_session_register with colliding l2tpv3 IDs
When handling colliding L2TPv3 session IDs, we use the existing
session IDR entry and link the new session on that using
session->coll_list. However, when using an existing IDR entry, we must
not do the idr_replace step.
Fixes: aa5e17e1f5ec ("l2tp: store l2tpv3 sessions in per-net IDR")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/l2tp/l2tp_core.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 29dfbd70c79c..1c1decce7f06 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -436,6 +436,7 @@ int l2tp_session_register(struct l2tp_session *session, struct l2tp_tunnel *tunnel) { struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + struct l2tp_session *other_session = NULL; u32 session_key; int err; @@ -456,11 +457,10 @@ int l2tp_session_register(struct l2tp_session *session, * support existing userspace which depends on it. */ if (err == -ENOSPC && tunnel->encap == L2TP_ENCAPTYPE_UDP) { - struct l2tp_session *session2; - - session2 = idr_find(&pn->l2tp_v3_session_idr, - session_key); - err = l2tp_session_collision_add(pn, session, session2); + other_session = idr_find(&pn->l2tp_v3_session_idr, + session_key); + err = l2tp_session_collision_add(pn, session, + other_session); } spin_unlock_bh(&pn->l2tp_session_idr_lock); } else { @@ -484,10 +484,12 @@ int l2tp_session_register(struct l2tp_session *session, spin_unlock_bh(&tunnel->list_lock); spin_lock_bh(&pn->l2tp_session_idr_lock); - if (tunnel->version == L2TP_HDR_VER_3) - idr_replace(&pn->l2tp_v3_session_idr, session, session_key); - else + if (tunnel->version == L2TP_HDR_VER_3) { + if (!other_session) + idr_replace(&pn->l2tp_v3_session_idr, session, session_key); + } else { idr_replace(&pn->l2tp_v2_session_idr, session, session_key); + } spin_unlock_bh(&pn->l2tp_session_idr_lock); trace_register_session(session); |